Hydroptila Dalman

Ito, Tomiko, 2021, Descriptions of final instar larvae of six species of the genus Hydroptila Dalman (Trichoptera, Hydroptilidae) in Japan, Zootaxa 4915 (3), pp. 339-350 : 339-340

Genus Hydroptila Dalman (Modified from Marshall 1979; Wells 1985; and Wiggins 1996)

Final instar larva. Head elongate, sides subparallel; ecdysial sutures indistinct; dorsal surface densely covered with minute spinules; mandibles asymmetrical. Thoracic dorsa each completely or incompletely covered with pairs of rectangular sclerotized nota, all densely covered with minute spinules; three ventral sclerites present on prothorax in some species; legs short and subequal; foretibiae each with distal ventral process well developed and bearing specialized setae. Abdomen slightly compressed laterally, distended, segments gradually enlarging from I to IV (or V), then decreasing, curvature of abdomen slight; dorsal chloride epithelia on some of segments I–VIII; large dorsal sclerite on segment IX; square dorsolateral sclerites on segment X; anal claws each with two or three accessary hooks; three filamentous gills on segments IX–X, one posterodorsal gill on segment IX and a pair of posterolateral gills on segment X.

Cases compressed laterally, composed of two ellipsoidal valves, with slit openings at anterior and posterior edges, made of fine sand grains, filamentous algae, or diatoms. Many species found in running waters, but some in standing waters such as ponds, lakes, and marshes.

Thirteen species-groups have been recognized in the genus but species groups are unknown for many species, and even Marshall (1979) considered her species groups far from satisfactory ( Wells & Huisman 1992).